1. Field of the Invention
The present invention relates to an air pump with a scale plate integrally disposed on the top surface of the base of the pump tube, in particular to a scale plate for measuring the air pressure.
2. Description of the Related Art
The newest technique of disposing the variometer on the base of an air pump is disclosed by FIG. 1 of Taiwan patent number I304454 whose title is “An air pump capable of varying in three kinds of air pressure” and FIG. 1 of Taiwan Utility Innovation number M410797 whose title is “An air pump put on the ground”.
However, the variometers of the prior patents have disadvantages as follows:
1. The conventional variometer is disposed at an outer side of the base, which renders the appearance of the product quite unusual, occupies the space and has difficulty in storing. Furthermore, it may easily cause harmful impact when carrying, so it is hard to achieve the demand of fine goods.
2. The conventional variometer is not adapted to a design with a bigger dimension since the problems of occupying the space and ease of carrying will become severe, which results in a variometer with a quite small scale that makes it difficult to clearly recognize the scale when read from a distance.
Therefore, in view of the disadvantages of the prior patents, the inventor has conceived, created and developed a more progressive invention.